Posted
by
samzenpuson Thursday April 04, 2013 @05:32AM
from the can-you-hear-me-now? dept.

An anonymous reader writes "Depending on the level of hearing impairment, conventional aids may not be good enough and a hearing implant is the only option. Until now the required surgery to fit them has taken several hours. However, that is about to change. A new implant that can be fitted with outpatient surgery has been developed consisting of a 1.2mm electro-acoustic transducer, which is positioned at the so-called 'round window,' which is where the middle and inner ear connect. It then produces amplified mechanical vibrations that stimulate the auditory nerve. Even though the transducer is tiny, it can reach volumes of up to 120 decibels."

I'm really kinda hoping we get a few more years before the surgically implanted Apple products arrive. First Apple makes surgically implanted monitoring devices seem cool, then the TSA requires them if you want to travel on commercial flights, then...

Cochlear implants [wikipedia.org] are required for some deaf patients, and those are the implants that require surgery. This PR bulletin from the Fraunhoffer institute is very cool, but it's like the retinal implants for vision, actually it's not even up to the level of retinal implants which are at least currently being tested. This implant system only has had its individual parts created..
Those individual components have not yet been put together to make a full hearing aid. This is just a proof of concept or feasibility study thus far. They still have to select the materials that will be used for the long term implantation. An assembled version may be ready next year. As for the extremely small size claimed, that small size is just for the "electroacoustic transducer" (the details in the PDF file says it's a piezoelectric micro-actuator). And the round window [wikipedia.org] is already the part of the ear that bulges in and out as the oval window accepts input from the stapedius. So this adds pressure on the other side of the fluid column.

Experts are currently testing a first working prototype in the laboratory. Results have been positive to date. "The individual components of the hearing aid have all been developed. The next step is to optimize and assemble them," says Kaltenbacher. The implant must measure up to high requirements: the material must be encased so the body tolerates it and it has to remain stable over long periods -- after all, hearing aid implants should last at least ten years. The optimized individual components should be ready by June of this year; testing of the overall system is planned for 2014.

1) battery? Either the battery has to last 10 years or you have to be able to replace it.2) amplification curve? Hearing loss typically has different attenuation at different frequencies, so modern aids amplify different frequencies differently, and some even shift the frequencies around.3) programming? Okay, if it just makes things louder, it doesn't need to be programmed but typically you need to have some way to adjust the configuration of the aid, and if it is instal

For 1, my best guess is that energy comes from an external transducer, coupled to a coil of the implant that can drive the actuator. Cochlear implants use this strategy (except they drive electrical impulses, not mechanical vibration)

Both 2 and 3 are handled by an external dsp. The implant piece is just the final acoustic amplifier / transducer; it is not driven by acoustical energy entering the ear, but by the signal being sent to it by the external device.

It's still interesting news, and good news. I knew an early cochlear implant user who had become deaf as a result of meningitis. He was stuck with a poor first generation implant - they were not exactly easy to upgrade.

I was implanted with implants in both ears just over a year ago. Overall, it is awesome - http://ihearnow.blogspot.com. The biggest complaint is that my processors are not wireless and I have occasional bouts of vertigo... It sure beats utter silence and my family/friends don't have to put up with the depression that happens when you lose your hearing...

your blog doesn't give me the impression that they are great. Not to mention it seems like it'll look like you have grey pads attached to your skull, roughly?

Audio does not sound as good as it did before the implants. I deleted about 2/3 of all my favorite mp3 songs. They were just not enjoyable anymore... Listening to music on TV is not as good either - so watching American Idol and XFactor is not the same now. These processors can only process sounds to something like 300 Hz (don't quote me on that),

These processors can only process sounds to something like 300 Hz (don't quote me on that), but a cello is something like 65 Hz.

A above middle C is 440 Hz. Two octaves down is 110 Hz. That's the lowest A on a cello. Just posting this to support your claim that the lowest note (C two octaves below middle C) is in fact 65.4... Hz.

They may not be 100% but they are something. Permanent silence vs being able to understand your family and friends or even your children again? I'll take some gray pads and disappointment with music.

I had a friend who lost his hearing and after 4 years of silence and one suicide attempt he had cochlear implants put in. Immediately after, his depression almost completely cleared and he was literally a different person. There are varying degrees at which implants do not make sense, also. For instance, my wife is deaf in one ear but to her, being able to hear in the one is enough (even though she can't tell where sounds are coming from or hear surround sound - I mess with her all the time of course) and she doesn't want an implant because of the specific reasons you quoted.

All in all, if you are completely deaf I think any hearing is better than no hearing. I wonder though...Beethoven was deaf and he composed some of the most incredible classical pieces of all time...if he had this technology available at the time, would he have given up on his musical talents because his pieces didn't sound the same anymore? I tend to think not but who knows.

I agree with you on some points. Hearing aids are definitely an improvement over not, but the problem is that hearing aids are designed and focus on "people talking" which ignores:

people singingmusicanything outside the normal range of people talking, which includes pitches people talk at when they're speaking softly.frequencies which you may be basically deaf for regardless of hearing aids because they just don't amplify them.

So they're really not "hearing aids" in the broad sense of the phrase which is w

Are you talking about hearing aids or cochlear implants here? Obviously there's a lot of work being put into both, but CIs arguably have a more difficult set of challenges to face if you want to talk about sounds signals other than speech, which is relatively well represented in the field for good reason. Music is always going to be a huge challenge with current CI technology due to the inherent limit of how many independent frequency channels you can stimulate (it's usually around 8, which is abysmal when

As a musician, I wish I had more background in formant research but I digress. Singing does not *entirely* match the frequencies and thus formants of people talking, and music doesn't necessarily match the formants of people singing. Meanwhile, frequency range vs true functionality/accurate reproduction of audio on even the highest end models of hearing aids from today's companies are fairly poor and tend to handle a very limited range of frequencies (by design). This is a problem. Whether it's BTE, ITC, i

Here's an odd thing about tinnitus -- I've been deaf in my left ear since age 5 from the mumps. As I understand it, the swelling suppressed the blood supply long enough to damage or kill the auditory nerve. The ear mechanism is probably fine but I'm deaf for lack of a communication link to the brain. I have tinnitus horribly. Weird thing is, I perceive hearing it in BOTH ears. Go figure. Make me wonder if it's a phenomena of the brain center rather than damaged receptors.

Yes, tinnitus is produced by the brain, not the inner ear. In my case I've had it pretty much my whole life. I was about 22 when I read a newspaper article about tinnitus, and was amazed. I had always assumed that *everyone's* ears rang all the time, had no idea that it was unusual. Now that I'm losing my hearing (hereditary factors) it's just getting worse.

I have a constant ringing in my right ear, and little bit in my left. Thankfully its not so bad as to drive me crazy, but its always there, in the background. In other words, I no longer have a sense of true silence. I blame wearing a shitty pair of headphones with the volume too high while exercising. If only I knew the damage I was doing!:/

Having severe hearing loss in one ear, this is very interesting to me, but honestly I would rather wait for results on current studies looking into regenerating damaged hair cells before pursuing this. The headline "Regaining Proper Hearing at Last" is in my opinion not quite correct; from what I can tell, they're just tickling whatever cells are left to stimulate harder than before, as opposed to restoring the full capability of input. Then you've still got signal processing issues like phase discrepancies, gaps in frequency coverage that need to be made up by transposing or saturating neighbor/harmonic frequencies, and all sorts of related hairy business. A big advantage here is you can break out the processing to a box with beefier DSP than you could fit in a BTE device, with batteries that last longer.

Definitely a step in the right direction, and by far better than similar solutions in the past, but still a long way from perfect.

That was also my impression. The mechanical nature of it seems to do just that. It also seems to avoid other issues that current aids have as its not an indirect digital amplifier. It's a direct amplifier, meaning that it doesn't attempt to reproduce sound that has been amplified, it amplifies the original analog signal.

The hair cells are inside the inner ear, later in the signal path than this device, and are responsible for turning the mechanical stimulus inside the inner ear into electrical signals. This device bypasses the outer ear and middle ear (depending on the placement of the microphone). Bypassing the hair cells means directly stimulating the auditory nerves, e.g. with electrical impulses such as is done by current cochlear implants.

Also, analog amplification does not imply no signal loss even within its 120 dB operating range (due to noise, nonlinear behavior, etc etc). It is also practically a guarantee that any end-product using this device will employ dynamic range compression, among other things, that will result in further loss of information in the signal. Regardless, it is still likely that the signal will amplified digitally by the external dsp, then transmitted finally as an analog signal to the implant. However that's not in the scope of this research, which focuses on the implanted device (just the final acoustic amplifier, one of many parts of a hearing aid system).

That's an interesting point - if a hearing loss is due to damaged hair cells, why simply batter those cells with more signal energy? The reason is this: there are two kinds of hair cells - outer hair cells (cells that vibrate in response to sound pressure) and inner hair cells (cells that send neural signals to the brain).
Our ~12,000 vibrating outer hair cells are electromechanical transducers that change shape in response to sound pressure. The ear works because the outer hair cells feed signal energy

For the same reason they haven't flooded any technology market with cheap, high quality goods. Because that is not their stong-point. Cheap, questionable quality (possibly toxic) hearing aids would be their market.

Of course you won't be able to have a Chinese hearing aid if you work for the US Government or want to maintain a US security clearance.

I imagine that more of the cost of a hearing aid is for costs related to FDA or other regulatory approval (and economic rents [wikipedia.org] that approved manufacturers collect for the fact that devices their have been approved) than for actual manufacturing costs.

This is dangerous technology. When a hearing aid goes wrong (and they often do), you can just take it off and turn it off. When this machine goes wrong, you lose your remaining hearing in a rather painful way.

It is capable of producing sounds up to 120 dB (assuming they meant dB SPL, or equivalent). This is not the same as 120 dB of amplification. (This is why those pesky letters SPL matter, and I'm surprised a Faunhofer report wasn't explicit). Of course, then the device could potentially detect a 0 dB SPL sound and amplify it to 120 dB, but that's really no different than any current technology, and it won't, and doesn't, happen.

So no, I have not seen anyone who wears hearing aids or cochlear implants scream and rip off their hearing aids or transmitters due to obscene amplification. Yes, I know plenty users of both (mostly young though).

Lastly, patients probably will have an off switch, and will also be able to take off the transmitters just like a CI user can.

Pretty much ANY transducer can do that... The key is the distance at which that rating is measured. For every halving of distance, you gain 6 dB additional output. Take a quiet 80 dB speaker at 1 meter, move it to 1 cm, and you've got 120 dB SPL. It's trivial to generate 120 dB SPL from an existing hearing aid - or this new unit - when it's placed in the auditory canal.

The article certainly lacks a clear definition of what is meant by "it can output volumes of up to 120 decibels". I assume they mean something equivalent to a 120 dB SPL sound measured at the entrance to the ear canal.

Here's the thing. It's an implant placed on the round window of the cochlea. So we're talking acoustic/mechanical coupling of solids, not spherical wave radiation. Talking about placing this unit in the ear canal doesn't make sense and implies that you didn't RTFS...say it isn't so , Slashdot.

The device attaches to the round window. It might someday be part of a hearing solution that could offer new hope to those with middle ear hearing loss (simply because it bypasses the middle ear). The cochlear implant is different. The cochlear implant bypasses the ear. The cochlear implant delivers a direct electrical signal through a fine strand of several electrodes set onto the auditory nerves. It sends a signal from a external receiver through an antenna directly to the auditory cortex without usi

Not quite direct to the auditory cortex, there are a lot of nerves and synapses between the auditory nerve and the auditory cortex. But this is just from someone who's been studying the peripheral auditory pathways for the past however long, so I may care a little more about those details than most:-) But, for example, there is a device called a auditory midbrain implant, that stimulates higher up in the signal pathway, but still far from cortex. Because of all the computations happening along the pathway